1. Field of the Invention
The present invention relates in general to the field of information handling systems, and more particularly to a method and system for information handling system heat sink retention.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Over the past several years, information handling systems have grown increasingly powerful as packaged electronic components used to manufacture information handling systems are designed to include greater processing power. For instance, central processing unit (xe2x80x9cCPUxe2x80x9d) designs operate at ever increasing speeds by reducing the size of their logical circuits to include greater numbers of transistors in a given CPU package. Information handling systems are typically built to include a number of packaged electronic components in relatively small housings, including in some instances multiple CPUs. One difficulty with the manufacture of information handling systems that include powerful packaged electronic components, such as multiple high speed CPUs, is that the heat generated by the packaged electronic components typically must be dissipated and removed from the housing to prevent the components from burning up. Generally, improved processing speeds for a packaged electronic component results in greater heat creation by that component.
In order to dissipate the increased heat generated by more powerful packaged electronic components, information handling systems have been manufactured with heat sinks having increased mass. Although, heat sinks having greater mass tend to have greater heat dissipation capabilities, more massive heat sinks take up increased space within an information handling system housing, thus making assembly of the information handling system more difficult. Further, increasing the mass of a heat sink generally increases the momentum of the heat sink during movement of the information handling system and thus makes secure attachment of the heat sink difficult under high acceleration loads. For instance, more massive heat sinks held in place by the bow spring device of U.S. Pat. No. 6,205,026 will have enough momentum under high acceleration loads to cause flexing of the bow springs that results in movement of the heat sink relative to a CPU. Since heat sinks are generally kept in contact with CPUs by heat conductive grease solutions, movement of the heat sink may result in movement of the CPU itself due to suction between the heat sink and the CPU. Under high acceleration loads with more massive heat sinks, the suction between the heat sink and the processor may actually pull the processor out of its socket, resulting in failure of the information handling system.
Therefore a need has arisen for a system and method which secures a heat sink proximate to a packaged electronic component with reduced space constraints to reduce the complexity of information handling system assembly.
A further need exists for a system and method which securely maintains a heat sink in conductive communication with a packaged electronic component to efficiently dissipate heat from the component while reducing the risk of excessive heat sink and component movement under acceleration loads.
In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous systems and methods for securing a heat sink proximate to a packaged electronic component of an information handling system. A retaining structure coupled to an information handling system planar rotationally secures the heat sink over the packaged electronic component.
More specifically, the retaining structure couples to a motherboard and has an opening through which a CPU is installed in a socket of the motherboard and a heat sink is secured over the CPU. The retaining structure has securing lips that extend into the opening and the heat sink has securing flanges that extend from its base. The securing flanges insert under the securing lips by rotationally engaging the heat sink until the flange and securing lip establish a predetermined assembly clearance between the base of the heat sink and the CPU. A locking detent associated with the retaining structure provides a downward bias to provide a thermal contact force between the heat sink and the CPU. The securing lip provides a rigid surface that restricts movement of the heat sink beyond the assembly clearance. A spring associated with the detent mechanism absorbs acceleration forces applied to the heat sink. In this manner, the retaining structure separates the application of thermal contact force and the shock load retention structure of the heat sink retention system.
The present invention provides a number of important technical advantages. One example of an important technical advantage is that a heat sink is secured proximate to a packaged electronic component with a reduced space needed for assembly of an information handling system. The heat sink drops into the retainer and rotates to a locked position without manipulation of secondary devices, such as clips. Further, the heat sink is easily removed to access the underlying packaged electronic component by rotating to unlock the heat sink and lifting the heat sink out of the retainer. Thus, assembly and disassembly of a heat sink uses only the footprint of the heat sink itself over the information handling system motherboard.
Another example of an important technical advantage of the present invention is that a heat sink is securely maintained in conductive communication with a packaged electronic component to efficiently dissipate heat from the component, yet the risk of excessive heat sink and component movement under acceleration loads is reduced by allowing only limited movement of the heat sink relative to the retainer. The heat sink is pressed against the packaged electronic component with a bearing structure of coil springs that allow movement of the heat sink; however, the amount of possible movement of the heat sink is restricted by the limited room between the heat sink base and the retention structure. This limited space for possible movement of the heat sink reduces the risk of removal of the packaged electronic component from its socket due to suction between the heat sink and the component.